Known air blowers usually include a housing and a motor and impeller accommodated in the housing. As shown in FIG. 1, the housing 1 includes a motor housing member 11 receiving the motor and an impeller housing member 12 receiving the impeller. The impeller housing member 12 and the motor housing member 11 are connected together. The impeller housing member 12 defines an opening 13 as an air inlet. The motor housing 11 defines a plurality of openings 14 as air outlets. The openings 14 are formed by cutouts parallel to an axis of the motor housing member 11 and are evenly arranged on an outer circumferential surface of the motor housing member 11.
During operation the motor drives the impeller to generate a pressurized airflow which is exhausted through the openings 14. This type of blower is commonly used in appliances such as hand dryers and vacuum cleaners. For example, the blowers used in hand dryers are required to deliver a large airflow to quickly dry hands and to have a small size to occupy a small space in the washrooms. However, there is a large air resistance to the pressurized airflow discharged from the air outlets, which causes the conventional blower to have a small airflow. In order to increase the airflow, an input power of the blower must be increased. As a result, the blower has a low overall efficiency. In addition, the blower has a large size.
Thus, there is a desire for a blower with increased efficiency and reduced size.